This conventional bogie has two pairs of wheels with axles viz a front pair of wheels and a rear pair of wheels for facilitating running of the wagon on rails. The wheels are firmly fitted on axle which rotates together while running and are held in position by the ‘H’ frame at end of axles through boxes. It is the ‘H’ frame which plays a major part for the total behaviour of the bogie.
There are disadvantages associated with the existing system of ‘H’ frame bogies.
One of the main disadvantages associated with the present system of conventional ‘H’ frame bogies is that when the wheels run on a pair of straight rail tracks, when there is a perfect alignment between the wheel flange and rail head and the wear of the wheel flange and rail head may be minimum.
This in general is not practicable during manufacture. When tolerances are applied the trueness of geometry is affected and wear propensity increases. Also when the wheels negotiate a curved track the wheel flange strikes the rail head at an angle called angle of the attack. Due to continuous rubbing of the wheel flange on rail head both wears very fast.
This phenomenon aggravates further with higher speed and higher haulage load. Since neither the speed nor the haulage loads could be reduced for economic reasons, this wheel wears can not be avoided in conventional bogie wheels and rail heads.
Another disadvantage associated with the present system of conventional ‘H’ frame bogies is that the bogie frame oscillates continuously and the rubbing faces wear rapidly causing increase in clearances between the ‘H’ frame and axle boxes of the wheels. Even when the frame is new, due to initial clearances, the conventional bogie tends to become unstable exhibiting a behaviour called ‘hunting’ at speeds above 50/55 k.m.p.h on straight track. This gets further agravated by a host of other factors like increased clearances, higher speed, higher axle loading, track/car geometry and rail profile.
Yet another disadvantage associated with the present conventional ‘H’ frame bogies is that the front pair of wheels and the rear pair of wheels being independent of each other and having clearances to play never negotiate the track rail tangentially.
In view of all above disadvantagaes, a fast moving bogie either on Tangent Track or when trying to negotiate a curved track will have its alignment lost because of lozenging effect of ‘H’ frame. Hence angle of attack, i.e. angle subtended by the wheel flange and rail head shall be very much high. Even in a bogie where the wheels are almost squarely with the frame, the angle of attack is of quite considerable amount.
As a result a conventional bogie is prone to:    a) excessive wheel wear,    b) wear of rail head and loss of rail head profile,    c) derailment caused by (a) & (b) above.
To overcome these disadvantages various attempt were made to improve the life of the bogie and the safety of operation at high speed. These are briefly described below:    1. Lubrication of rail head for reducing wheel wear and rail wear by automatic spraying of oil at the negotiating curved track.
This has not been found very much productive/effective in view of wheels touching the rails at a very wide angle and at a very high speed and high momentum value.    2. Cross Brace Bogie has been developed to maintain alignment of bogie/truck wheels by providing cross bracings diagonally for meeting wheel alignment or squarity at each diagonally opposite ends of the bogie.
The system suffers from being too fragile for heavy rough work needed for wagons or freight cars moving at high speed over rough track condition. The system definitely requires repeated maintenance. The replacement costs are quite high.    3. A C-Type Cast Steel Steering Arm is a single piece casting connected with the axle box adapter at end of axles. This single piece casting is very heavy and reduces the carrying capacity appreciably to the extent of its self weight. This system requires side lining of the wagon/car for a considerable period for maintenance or over hauling of the steering device or the bogie.
The wagon superstructure is to be fully removed to have access for even general maintenance work required for the Bogie steering arms. Even a localised defect may require total replacement of the arm resulting into added cost. Adapters are connected only on inside lugs resulting into lesser amount of grip on axle journals.    4. C-Type fabricated Mild Steel Steering Arm has so far been designed with welded flat sections involving large amount of weld metal deposition which leads to distortions of the arm after welding. These are rectified by heavy press work which causes internal stresses in the arm as well as in the weld bids. The initial distortion tries to come back due to constant stress and stress during service and the geometry gets lost.
Out of the above four types of improved bogies, the last one namely the ‘C-type fabricated mild steel steering arm’ has partially improved the performance but for the drawbacks or disadvantages as mentioned.
There are many types of steering bogies which are in service mostly in Meter Gauge and some in the Standard Gauge. The Meter Gauge bogies are known as “Scheffel Cross Anchor Bogie” which run on 1067 mm track gauge. There are other versions of this bogie known as “Barber Radial”, “Amsted AR-1” and “Amsted AR2” which are on the 1435 mm track gauge. These bogies have the ‘C’ Arms only for in-board type of different constructional details.
The present invention is for improved and easy construction of in-board steering mechanism and also newly invented out-board steering mechanism.
There are no steering bogies where the steering device can be retrofitted on the existing bogies in service. This type of steering mechanism of the invention has the ability to render the vendor to retrofitment on the existing bogies. In addition to such retrofitment, the same will additionally accommodate retrofitment of clasp Brake and Bogie Mounted Brake.